I'm about to get a set of spare tires for the RT12. Right now I've got the Continental VMAX on it, 235's in front and 325/30/19's in back, on the OZ's.

At this point, my choices are down to:

PS2's 345/30 in back or MPSC's 325/30 in back (easy to get the front tires in the original sizes with either tire).

Some questions for you guys:

1) What kind of mileage can I get out of the MPSC's?

I've got MPSC's on my GT3 and the insides grooves are totally gone after around 3,700miles/6000kms. But the car is driven on the track, whereas the Ruf won't be doing much track duty at all, if any. So assuming purely street miles, how long can I expect these to last?

2) Is it ok to use the PS2's even if they're not "N" rated for Porsche?

The PS2's in 345/30 are "C" rated for Viper. Will that make a real difference for street driving? The Ruf does a lot of high speed running, but not a whole lot of heavy cornering...

(BTW, i know the 345/30's are marginally larger in rolling diameter than the tires i've got now... but its about a 1.7% difference, which I believe is acceptable)

Thanks in advance!